PROJECT ABSTRACT Trauma is the leading cause of death and disability worldwide, killing more people under the age of 36 than all other causes combined. Coagulopathy in trauma patients can result from multiple factors: 1) trauma-induced coagulopathy (TIC), an endogenous state of impaired coagulation that happens before treatment, is consistently identified in a quarter of trauma patients; 2) suboptimal care of patients, such as hypothermia or hemodilution, can also cause or further compound coagulopathy. Given that 30% of deaths caused by trauma coagulopathy occur within the first hour, rapid detection and aggressive correction of the condition can dramatically improve patient outcomes and save lives. Fibrinogen plays a crucial role in the pathogenesis and management of trauma coagulopathy. Fibrinogen is the most vulnerable coagulation factor during hemorrhage, reaching critically low levels earlier than any other factor. Prompt measurement and data-driven replacement of fibrinogen is now part of current European guidelines for management of hemorrhage and coagulopathy and is increasingly advocated for in the US. Early measurement of fibrinogen is actionable: it can not only guide decisions on fibrinogen replacement, but also facilitate other clinical decisions for managing coagulopathy, such as initiation of massive transfusion. We propose to create a rapid POC test for fibrinogen, with a simple and robust design to enable use in prehospital and Emergency Department (ED) settings. We will use our device to measure whole blodd and plasma samples from 40 patients in phase 1, and compare with the commonly used Clauss assay. If successful, this work has the potential to yield the first point of care fibrinogen test to provide life-saving information at the time of need.